[Callers] Leading a 1 hr contra dance

I have a gig coming up at a library wherein I have one hour to teach and call contra dances. It's a mixed crowd, and I heard there may be a lot of tweens present. I think I'd like to focus on bigger picture things - moving up and down the line, swinging, interacting with their set. I imagine I may even cut out courtesy turns in order to minimize the time we spend on the lesson. I've taught for small, mostly inexperienced crowds before but I usually have a lot more time. I'd really rather get them moving than to get bogged down in teaching. Does anyone have insight, suggestions, or advice? Thanks, Liz Burkhart